2013
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This preliminary report will provide a geochemical and ionic characterisation of groundwater, to determine baseline conditions and, if possible, to distinguish between different aquifers in the Laura basin. The groundwater quality data will be compared against the water quality guidelines for aquatic ecosystem protection, drinking water use, primary industries, use by industry, recreation and aesthetics, and cultural and spiritual values to assess the environmental values of groundwater and the treatment that may be required prior to reuse or discharge.
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Invited entry for reference on 'Encycolpedia of Scientific Dating Methods' about uranium-lead dating of detrital zircon.
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Watertable contours were constructed from recent water level data in the state databases of NSW and Queensland. SA and NT data points were from Flinders University. SA water levels were corrected for density effects due to salinity. Elsewhere, density corrections for the watertable aquifer are not deemed to be an issue. Similar to the confined aquifers, regional groundwater flow in the watertable aquifers is from the highest potentials in the intake beds on the western slopes of the Great Dividing Range (GDR) in New South Wales and Queensland. This intake zone extends northward along the western slopes of the GDR to the tip of Cape York where the pressures are lower than those in the southern recharge area. The watertable lies in the Jurassic formations in the intake beds but basinward it passes into the Early Cretaceous formations (Winton (Kw) and Mackunda (Klm) Formations in the Eromanga Basin, Griman Creek Formation in the Surat Basin). These aquifers comprise the most areally extensive host for the watertable in the GAB. In the Lake Eyre and Karumba Basins, the watertable passes into Cenozoic sediments. Regional discharge zones for the watertable are Lake Eyre and an eastward arcuate band of salt lakes extending from Lake Frome to Lake Gregory. Both of these regional discharge zones lie in SA but there is another intra-basin discharge area at the Bulloo Overflow/Caryapundy Swamp on the NSW/Queensland border. Regional discharge from the watertable in the Carpentaria/Karumba Basins is the Gulf of Carpentaria. Regional discharge from the Coonamble Embayment watertable is the Darling River alluvium. There are subtle features evident in the watertable map which distinguish it from the potentiometric surface map of the Hooray Sandstone (JKh) confined aquifer. - The watertable contours are not smooth like the JKh contours, but form local recharge mounds extending far into the basin. Some of these recharge mounds are coincident with structures like the Innamincka Dome and all of them occur in areas mapped as Kw or Klm outcrop, or in areas where the Lower Cretaceous rocks are shallowly buried by Cenozoic sediments. In the Eromanga Basin, the total intra-basin recharge into the Kw and Klm aquifers is estimated to be 164 GL/year which is 21 GL/year higher than recharge to the Hooray and Hutton Sandstones on the western slopes of the GDR. Intra-basin recharge has never before been included in GAB water budgets. - The two largest rivers in the Eromanga Basin, the Diamantina River and the Cooper Creek are prominent watertable drains. By way of contrast, there is no apparent relationship between these major streams and the JKh potentiometry. - The watertable mounds along the Eulo Ridge and their extension south-westwards toward the Yancannia Range in NSW come close to forming a groundwater divide between the Surat and Eromanga Basins, but the line of mounds is breached in some places permitting impeded lateral throughflow. For the watertable, the Eulo Ridge acts as is an impermeable subsurface boundary but there is no apparent influence of this structure or its hydrogeological role on the JKh potentiometry.
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The data set provides outlines for the maximum extent of the benthic Biomes of Australia's Exclusive Economic Zone for regions beyond the shelf break not including the offshore island territories and Australian Antarctic Territory. These data were compiled in 2004 as part of the draft national benthic marine bioregionalisation which is designed to provide improved knowledge of Australia's seabed. The Biomes represent bio-geographic regions that capture narrow spatial distributions and depth ranges in benthic faunal distributions, based on the assumption that the demersal fish distributions are a surrogate of marine faunal distributions. The narrow spatial distributions were revealed as strong patterns of bathymetric zoning for key indicator species on the upper to mid slope. Due to available data, biomes were only defined in water depths of <1,130 m. A total of three biomes were defined: upper slope, mid-upper slope, and mid slope. Each of the biomes is separated by a biotone. The Biomes data set includes the names of units in the attribute table as well as the area and perimeter of each unit.
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These colour and greyscale images are digital pictorial representations of a grid of onshore Bouguer Anomaly station values (Bouguer density of 2.67 t/m3) and offshore free air pseudo gravity station values extracted from the World Gravity Image (Sandwell and Smith, 1995). The onshore gravity observations are held in the Australian National Gravity Database (1997). These images contain wavelengths as small as 5000 m. Gravity digital data are available in point located form or as a grid for the Australian continent as a whole or for smaller areas.
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These colour and greyscale images are digital pictorial representations of a grid of onshore Bouguer Anomaly station values (Bouguer density of 2.67 t/m3) and offshore free air pseudo gravity station values extracted from the World Gravity Image (Sandwell and Smith, 1995). The onshore gravity observations are held in the Australian National Gravity Database (1997). These images contain wavelengths as small as 30 000 m. Gravity digital data are available in point located form or as a grid for the Australian continent as a whole or for smaller areas.
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Formation and preservation of many mineral deposits, including volcanic-hosted massive sulphide(VHMS) and lode gold deposits, is tied to supercontinent/supercraton assembly. Rodinia assembly differed from other supercontinents in that it lacks deposits typically associated with assembly, and did not produce large quantities of juvenile crust. In other ways Rodinia assembly was similar to other supercontinents: it included significant crustal thickening, as indicated by peaks in metamorphic zircon growth and pegmatite emplacement, and involved a significant pulse of felsic magmatism as indicated by the distribution of detrital zircons in river sands. Importantly, this pulse of detrital zircon is not matched by a peak in preserved felsic magmatism, indicating these rocks were lost to erosion. These patterns reflect geological processes and are not an artefact of inadequate data or exploration. We propose that the paucity of mineralisation associated with Rodinia assembly could result from the dominance of advancing accretionary orogenesis (e.g., East Pacific (Andean)-type margins), in contrast to other periods of supercontinent assembly that were dominated by retreating accretion (e.g., West Pacific-type margins). Although porphyry-epithermal deposits form in both margin types, VHMS and lode gold deposits are enhanced by development of back-arc basins along retreating margins which provide a setting for VHMS mineralisation and the structural framework reactivated during lode gold mineralising events. These settings would be inhibited if supercontinent assembly was dominated by advancing accretionary orogenesis. Our analysis suggests that explorationists should consider the style of accretion during area selection, as it could have a significant effect on potential for mineralisation.
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The data represents the possibility that the substrate is rocky. It was created from the averaged topographic relief layer. The data values range from 0 to 100.
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Geoscience Australia carried out marine surveys in southeast Tasmania in 2008 and 2009 (GA0315) to map seabed bathymetry and characterise benthic environments through observation of habitats using underwater towed video. Data was acquired using the Tasmania Aquaculture and Fisheries Institute (TAFI) Research Vessel Challenger. Bathymetric mapping was undertaken in seven survey areas, including: Freycinet Pensinula (83 sq km, east coast and shelf); Tasman Peninsula (117 sq km, east coast and shelf); Port Arthur and adjacent open coast (17 sq km); The Friars (41 sq km, south of Bruny Island); lower Huon River estuary (39 sq km); D Entrecastreaux Channel (7 sq km, at Tinderbox north of Bruny Island), and; Maria Island (3 sq km, western side). Video characterisations of the seabed concentrated on areas of bedrock reef and adjacent seabed in all mapped areas, except for D Entrecastreaux Channel and Maria Island. sisters_160 is an ArcINFO grid of the sisters, north of Tasman Peninsula survey area produced from the processed EM3002 bathymetry data using the CARIS HIPS and SIPS software
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Vegetation index time series generated from coarse resolution sensors such as MODIS, MERIS and AVHRR have long been used to characterize land cover, land cover change and vegetation dynamics. However such techniques have not typically been applied to moderate resolution data i.e. Landsat data due to challenges associated with automated atmospheric correction, view angle normalization, BRDF correction and automated cloud/cloud shadow/pixel saturation. However operational approaches that address these challenges [1][2] and [3] have recently been implemented on national archives of Landsat imagery. These two developments make it possible to generate a vegetation index time series at Landsat scales. Furthermore, the conversion of digital numbers to surface reflectance makes it possible to use surface reflectance measurements made by Landsat-5 TM and Landsat-7 ETM+ [4] to create a time series that consists of measurements made by both sensors. The capacity to generate 25 metre resolution vegetation index time series represents an important development in our capacity to monitor food production systems and native vegetation communities from both a productivity and vegetation condition perspective. The capacity to create time series from multiple sensors is a critical step in enabling systematic analysis of deep archives of satellite imagery so that we can compare the changes taking place now with those that have occurred in the past.